Risk of transmission of SARS-CoV-2 on international flights, a retrospective cohort study using national surveillance data in England.

BACKGROUND: It is not yet fully understood to what extent in-flight transmission contributed to the spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This study aimed to determine the occurrence and extent of SARS-CoV-2 transmission in-flight and assess factors associated with transmission risk to inform future control strategies. METHODS: Retrospective cohort study using data obtained from contact tracing of international flights arriving in England between 02/08/2021-15/10/2021. Transmission risk was estimated by calculating the secondary attack rate (SAR). Univariable and multivariable analyses of the SAR by specific risk factors was undertaken, including: number of in-flight index cases; number of symptomatic index cases; contact vaccination status; flight duration; proximity to the index case(s); contact age. RESULTS: 11,307 index cases linked to 667,849 contacts with 5,289 secondary cases reported. In-flight SAR was 0.79% (95% CI: 0.77-0.81). Increasing numbers of symptomatic cases (when > 4 index cases compared to one index case aOR 1.85; 95% CI: 1.40-2.44) and seating proximity to an index case (seated within compared to outside of two rows OR 1.82; 95% CI: 1.50-2.22) were associated with increased risk of secondary cases. Full vaccination history was protective (aOR 0.52; 95% CI: 0.47-0.57). CONCLUSIONS: This study confirms that in-flight transmission of SARS-CoV-2 occurred. There are factors associated with increased risk of infection. Contact tracing identified exposed persons who subsequently developed infection. A targeted approach to contact tracing passengers with the highest exposure risk could be an effective use of limited public health resources.

Epidemiology of Early Monkeypox Virus Transmission in Sexual Networks of Gay and Bisexual Men, England, 2022.

After community transmission of monkeypox virus was identified in Europe, interviews of 45 case-patients from England indicated transmission in international sexual networks of gay and bisexual men since April 2022. Interventions targeting sex-on-premises venues, geospatial dating applications, and sexual health services are likely to be critical for outbreak control.

Community transmission of monkeypox in the United Kingdom, April to May 2022.

Between 7 and 25 May, 86 monkeypox cases were confirmed in the United Kingdom (UK). Only one case is known to have travelled to a monkeypox virus (MPXV) endemic country. Seventy-nine cases with information were male and 66 reported being gay, bisexual, or other men who have sex with men. This is the first reported sustained MPXV transmission in the UK, with human-to-human transmission through close contacts, including in sexual networks. Improving case ascertainment and onward-transmission preventive measures are ongoing.

Transmission dynamics of COVID-19 in household and community settings in the United Kingdom, January to March 2020.

BackgroundHouseholds appear to be the highest risk setting for COVID-19 transmission. Large household transmission studies in the early stages of the pandemic in Asia reported secondary attack rates ranging from 5 to 30%.AimWe aimed to investigate the transmission dynamics of COVID-19 in household and community settings in the UK.MethodsA prospective case-ascertained study design based on the World Health Organization FFX protocol was undertaken in the UK following the detection of the first case in late January 2020. Household contacts of cases were followed using enhanced surveillance forms to establish whether they developed symptoms of COVID-19, became confirmed cases and their outcomes. We estimated household secondary attack rates (SAR), serial intervals and individual and household basic reproduction numbers. The incubation period was estimated using known point source exposures that resulted in secondary cases.ResultsWe included 233 households with two or more people with 472 contacts. The overall household SAR was 37% (95% CI: 31-43%) with a mean serial interval of 4.67 days, an R0 of 1.85 and a household reproduction number of 2.33. SAR were lower in larger households and highest when the primary case was younger than 18 years. We estimated a mean incubation period of around 4.5 days.ConclusionsRates of COVID-19 household transmission were high in the UK for ages above and under 18 years, emphasising the need for preventative measures in this setting. This study highlights the importance of the FFX protocol in providing early insights on transmission dynamics.

Epidemiological and clinical characteristics of early COVID-19 cases, United Kingdom of Great Britain and Northern Ireland.

OBJECTIVE: To describe the clinical presentation, course of disease and health-care seeking behaviour of the first few hundred cases of coronavirus disease 2019 (COVID-19) in the United Kingdom of Great Britain and Northern Ireland. METHODS: We implemented the World Health Organization's First Few X cases and contacts investigation protocol for COVID-19. Trained public health professionals collected information on 381 virologically confirmed COVID-19 cases from 31 January 2020 to 9 April 2020. We actively followed up cases to identify exposure to infection, symptoms and outcomes. We also collected limited data on 752 symptomatic people testing negative for COVID-19, as a control group for analyses of the sensitivity, specificity and predictive value of symptoms. FINDINGS: Approximately half of the COVID-19 cases were imported (196 cases; 51.4%), of whom the majority had recent travel to Italy (140 cases; 71.4%). Of the 94 (24.7%) secondary cases, almost all reported close contact with a confirmed case (93 cases; 98.9%), many through household contact (37 cases; 39.8%). By age, a lower proportion of children had COVID-19. Most cases presented with cough, fever and fatigue. The sensitivity and specificity of symptoms varied by age, with nonlinear relationships with age. Although the proportion of COVID-19 cases with fever increased with age, for those with other respiratory infections the occurrence of fever decreased with age. The occurrence of shortness of breath also increased with age in a greater proportion of COVID-19 cases. CONCLUSION: The study has provided useful evidence for generating case definitions and has informed modelling studies of the likely burden of COVID-19.

The COVID-19 pandemic: a new challenge for syndromic surveillance.

The COVID-19 pandemic is exerting major pressures on society, health and social care services and science. Understanding the progression and current impact of the pandemic is fundamental to planning, management and mitigation of future impact on the population. Surveillance is the core function of any public health system, and a multi-component surveillance system for COVID-19 is essential to understand the burden across the different strata of any health system and the population. Many countries and public health bodies utilise 'syndromic surveillance' (using real-time, often non-specific symptom/preliminary diagnosis information collected during routine healthcare provision) to supplement public health surveillance programmes. The current COVID-19 pandemic has revealed a series of unprecedented challenges to syndromic surveillance including: the impact of media reporting during early stages of the pandemic; changes in healthcare-seeking behaviour resulting from government guidance on social distancing and accessing healthcare services; and changes in clinical coding and patient management systems. These have impacted on the presentation of syndromic outputs, with changes in denominators creating challenges for the interpretation of surveillance data. Monitoring changes in healthcare utilisation is key to interpreting COVID-19 surveillance data, which can then be used to better understand the impact of the pandemic on the population. Syndromic surveillance systems have had to adapt to encompass these changes, whilst also innovating by taking opportunities to work with data providers to establish new data feeds and develop new COVID-19 indicators. These developments are supporting the current public health response to COVID-19, and will also be instrumental in the continued and future fight against the disease.

The epidemiology and management of clusters of invasive meningococcal disease in England, 2010-15.

BACKGROUND: Guidance for public health management of invasive meningococcal disease (IMD) in in England recommends the use of antibiotic chemoprophylaxis and vaccination. We summarized clinical and epidemiological data collected during routine management of IMD clusters in England. METHODS: Data on epidemiology and operational decisions for public health management were reviewed for clusters between April 2010 and December 2015. RESULTS: Clusters were generally 2-3 cases (53/58; 91%) within a single age band <18-years. Nurseries (n = 20, 34%), households/social networks (n = 14, 24%) and schools (n = 10, 17%) were the commonest settings. Chemoprophylaxis alone was used in 36 (58%) clusters, including most serogroup B clusters (31/41; 76%). Chemoprophylaxis and vaccination was used in a further 20 (32%) clusters. Vaccine was delivered promptly (<7 days). Four clusters had cases with onset post-chemoprophylaxis; no clusters recorded cases with onset post-vaccination. No pattern was observed between interventions and setting/population at risk, and interventions were consistent with national guidance. Challenges to management included logistical issues related to intervention delivery. CONCLUSIONS: Public health management of IMD clusters presents challenges in decision-making and implementation of interventions. Nonetheless, few cases were observed following intervention. Responses were consistent with national guidance. A systematic data collection tool should be developed to support future evaluation.

Emergency department syndromic surveillance systems: a systematic review.

BACKGROUND: Syndromic surveillance provides public health intelligence to aid in early warning and monitoring of public health impacts (e.g. seasonal influenza), or reassurance when an impact has not occurred. Using information collected during routine patient care, syndromic surveillance can be based on signs/symptoms/preliminary diagnoses. This approach makes syndromic surveillance much timelier than surveillance requiring laboratory confirmed diagnoses. The provision of healthcare services and patient access to them varies globally. However, emergency departments (EDs) exist worldwide, providing unscheduled urgent care to people in acute need. This provision of care makes ED syndromic surveillance (EDSyS) a potentially valuable tool for public health surveillance internationally. The objective of this study was to identify and describe the key characteristics of EDSyS systems that have been established and used globally. METHODS: We systematically reviewed studies published in peer review journals and presented at International Society of Infectious Disease Surveillance conferences (up to and including 2017) to identify EDSyS systems which have been created and used for public health purposes. Search criteria developed to identify "emergency department" and "syndromic surveillance" were applied to NICE healthcare, Global Health and Scopus databases. RESULTS: In total, 559 studies were identified as eligible for inclusion in the review, comprising 136 journal articles and 423 conference abstracts/papers. From these studies we identified 115 EDSyS systems in 15 different countries/territories across North America, Europe, Asia and Australasia. Systems ranged from local surveillance based on a single ED, to comprehensive national systems. National EDSyS systems were identified in 8 countries/territories: 2 reported inclusion of ≥85% of ED visits nationally (France and Taiwan). CONCLUSIONS: EDSyS provides a valuable tool for the identification and monitoring of trends in severe illness. Technological advances, particularly in the emergency care patient record, have enabled the evolution of EDSyS over time. EDSyS reporting has become closer to 'real-time', with automated, secure electronic extraction and analysis possible on a daily, or more frequent basis. The dissemination of methods employed and evidence of successful application to public health practice should be encouraged to support learning from best practice, enabling future improvement, harmonisation and collaboration between systems in future. PROSPERO NUMBER: CRD42017069150 .

Syndromic surveillance: two decades experience of sustainable systems - its people not just data!

Syndromic surveillance is a form of surveillance that generates information for public health action by collecting, analysing and interpreting routine health-related data on symptoms and clinical signs reported by patients and clinicians rather than being based on microbiologically or clinically confirmed cases. In England, a suite of national real-time syndromic surveillance systems (SSS) have been developed over the last 20 years, utilising data from a variety of health care settings (a telehealth triage system, general practice and emergency departments). The real-time systems in England have been used for early detection (e.g. seasonal influenza), for situational awareness (e.g. describing the size and demographics of the impact of a heatwave) and for reassurance of lack of impact on population health of mass gatherings (e.g. the London 2012 Olympic and Paralympic Games).We highlight the lessons learnt from running SSS, for nearly two decades, and propose questions and issues still to be addressed. We feel that syndromic surveillance is an example of the use of 'big data', but contend that the focus for sustainable and useful systems should be on the added value of such systems and the importance of people working together to maximise the value for the public health of syndromic surveillance services.

Effect of general practice characteristics and antibiotic prescribing on Escherichia coli antibiotic non-susceptibility in the West Midlands region of England: a 4 year ecological study.

Objectives: To assess the effect of general practice characteristics and antibiotic prescribing on the number of non-susceptible Escherichia coli isolated from urine specimens submitted from community settings, we undertook an ecological study of the general practice population in the West Midlands. Methods: Descriptive analysis and multilevel modelling of temporal trends in antibiotic prescribing and non-susceptibility of E. coli urine isolates to a range of antibiotics prescribed in the community over a 4 year period. Results: Nine of the 16 antibiotic prescribing/non-susceptibility combinations demonstrated a significant statistical linear correlation with non-susceptibility either for prescribing in a quarter or for prescribing within the previous 12 months. The magnitude of the effect varied, from a 0.3% increase in the odds of non-susceptibility to ampicillin/amoxicillin (when prescribing ampicillin/amoxicillin) to a 6.3% increase in the odds of non-susceptibility to nitrofurantoin (when prescribing nitrofurantoin) for an increase of 50 DDDs per 1000 practice population within a quarter (equivalent to ∼10 courses of antibiotics). In all 16 models, single-handed general practices were shown to have a significant association with increased numbers of non-susceptible E. coli urine isolates (adjusted ORs 1.083-1.657). Increased prescribing of ampicillin/amoxicillin in winter periods was associated with increased non-susceptibility of E. coli isolated from urine specimens. Conclusions: Small increases in antibiotic prescribing in individual general practices reduce the number of susceptible bacteria in the practice population. To maintain the effectiveness of available treatment, antibiotic stewardship should be encouraged and supported within each practice.

Google search patterns monitoring the daily health impact of heatwaves in England: How do the findings compare to established syndromic surveillance systems from 2013 to 2017?

One of the implications of climate change is a predicted increase in frequent and severe heatwaves. The impact of heatwaves on the health of the population is captured through real-time syndromic healthcare surveillance systems monitored daily in England during the summer months. Internet search data could potentially provide improved timeliness and help to assess the wider population health impact of heat by capturing a population sub-group who are symptomatic but do not seek healthcare. A retrospective observational study was carried out from June 2013 to September 2017 in England to compare daily trends in validated syndromic surveillance heat-related morbidity indicators against symptom-based heatwave related Google search terms. The degree of correlation was determined with Spearman correlation coefficients and lag assessment was carried out to determine timeliness. Daily increases in frequency in Google search terms during heatwave events correlated well with validated syndromic indicators. Correlation coefficients between search term frequency and syndromic indicators from 2013 to 2017 were highest with the telehealth service NHS 111 (range of 0.684-0.900 by search term). Lag analysis revealed a similar timeliness between the data sources, suggesting Google data did not provide a delayed or earlier signal in the context of England's syndromic surveillance systems. This work highlights the potential benefits for countries which lack established public health surveillance systems to monitor heat-related morbidity and the use of internet search data to assess the wider population health impact of exposure to heat.

Novel public health risk assessment process developed to support syndromic surveillance for the 2012 Olympic and Paralympic Games.

Background: Syndromic surveillance aims to provide early warning and real time estimates of the extent of incidents; and reassurance about lack of impact of mass gatherings. We describe a novel public health risk assessment process to ensure those leading the response to the 2012 Olympic Games were alerted to unusual activity that was of potential public health importance, and not inundated with multiple statistical 'alarms'. Methods: Statistical alarms were assessed to identify those which needed to result in 'alerts' as reliably as possible. There was no previously developed method for this. We identified factors that increased our concern about an alarm suggesting that an 'alert' should be made. Results: Between 2 July and 12 September 2012, 350 674 signals were analysed resulting in 4118 statistical alarms. Using the risk assessment process, 122 'alerts' were communicated to Olympic incident directors. Conclusions: Use of a novel risk assessment process enabled the interpretation of large number of statistical alarms in a manageable way for the period of a sustained mass gathering. This risk assessment process guided the prioritization and could be readily adapted to other surveillance systems. The process, which is novel to our knowledge, continues as a legacy of the Games.

Use of antimicrobial resistance information and prescribing guidance for management of urinary tract infections: survey of general practitioners in the West Midlands.

BACKGROUND: There is a marked variation in both antibiotic prescribing practice and urine sampling rates for diagnostic microbiology across general practices in England. To help understand factors driving this variation, we undertook a survey in 2012/13 to determine sampling protocols and antibiotic formularies used by general practitioners (GPs) for managing urinary tract infections (UTIs) in the West Midlands region of England. METHOD: Cross-sectional survey of all eligible general practices in the West Midlands region of England undertaken in November 2012. GPs were invited to complete an online survey questionnaire to gather information on policies used within the practice for urine sampling for microbiological examination, and the source of antibiotic formularies used to guide treatment of UTIs. The questionnaire also gathered information on how they would manage five hypothetical clinical scenarios encountered in the community. RESULTS: The response rate was 11.3 % (409/3635 GPs), equivalent to a practice response rate of 26 % (248/950). Only 50 % of GPs reported having a practice policy for urine sampling. Although there was good agreement from GPs regarding collecting specimens in scenarios symbolising treatment failure (98 %), UTI in an adult male (98 %) and asymptomatic UTI in pregnancy (97 %), there was variation in GPs requesting a specimen for the scenarios involving a suspected uncomplicated urinary tract infection (UTI) and an asymptomatic catheterised elderly patient; with 40 and 38 % respectively indicating they would collect a specimen for microbiological examination. CONCLUSION: Standardised evidence based clinical management policies and antibiotic formularies for GPs should be readily available. This will promote the rational use of diagnostic microbiology services, improve antimicrobial stewardship and aid the interpretation of ongoing antimicrobial resistance surveillance.

School outbreak of Escherichia coli O157 with high levels of transmission, Staffordshire, England, February 2012.

BACKGROUND: Verocytotoxin-producing Escherichia coli (VTEC) are bacteria that cause infectious gastroenteritis and in certain settings can cause widespread infection due to secondary transmission. We describe the findings of an investigation of a school-based outbreak of VTEC in Staffordshire, England. METHODS: Outbreak investigation at a school in February 2012 after two children were diagnosed with VTEC infection. Cases were defined as pupils and staff (or their household contacts) with gastrointestinal symptoms or asymptomatic screened persons, with laboratory confirmed VTEC O157 infection (phage type 32, verocytotoxin 2) occurring on or after 1 February 2012. Microbiological tests of food and faecal samples plus screening of asymptomatic contacts were undertaken. Epidemiological and clinical data were descriptively analysed. RESULTS: Thirty-eight cases were detected. Nineteen were asymptomatic and identified via screening of 191 pupils. Infection was introduced into the school from an earlier household cluster, followed by extensive person-to-person transmission within the nursery/infant group with limited spread to the wider school population. CONCLUSIONS: Control measures included several interventions, in particular, universal screening of pupils and staff. Screening during school outbreaks is not underpinned by guidance but proved to be a key control measure. Screening of asymptomatic contacts should be considered in similar outbreaks.

Surveillance of antibiotic susceptibility of urinary tract pathogens for a population of 5.6 million over 4 years.

OBJECTIVES: To retrospectively analyse routine susceptibility testing data to describe antimicrobial non-susceptibility trends in isolates of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa from urine samples in a population of 5.6 million people over a 4 year period. METHODS: De-duplicated laboratory data submitted to the AmSurv surveillance system from the West Midlands region of England and results of submissions to the Antimicrobial Resistance and Healthcare Associated Infections Reference Unit were extracted for the period 2010-13. Descriptive analysis of the non-susceptibility of selected Gram-negative organisms to key antibiotics, as recommended for monitoring in the UK Five Year Antimicrobial Resistance Strategy, was undertaken. RESULTS: During the study period, there were 431 461 reports for E. coli, 23 786 for K. pneumoniae and 6985 for P. aeruginosa from urine specimens. These represented 61%, 3% and 1%, respectively, of all organisms isolated from urine specimens. There was a linear increase in non-susceptibility to third-generation cephalosporins for E. coli and K. pneumoniae, and to ciprofloxacin for E. coli, in specimens from both hospital and community settings (P < 0.001). The proportions of E. coli and K. pneumoniae reported non-susceptible to meropenem and/or imipenem remained low during the study period, with no evidence of linear trend (P ≥ 0.05). CONCLUSIONS: Automated antimicrobial resistance surveillance enabled, for the first time in England, the systematic monitoring of resistance in bacteria responsible for urinary tract infections in a defined population, and thereby provided a representative indication of the burden of resistance in Gram-negative bacteria in hospital and community settings.

Strategies for controlling non-transmissible infection outbreaks using a large human movement data set.

Prediction and control of the spread of infectious disease in human populations benefits greatly from our growing capacity to quantify human movement behavior. Here we develop a mathematical model for non-transmissible infections contracted from a localized environmental source, informed by a detailed description of movement patterns of the population of Great Britain. The model is applied to outbreaks of Legionnaires' disease, a potentially life-threatening form of pneumonia caused by the bacteria Legionella pneumophilia. We use case-report data from three recent outbreaks that have occurred in Great Britain where the source has already been identified by public health agencies. We first demonstrate that the amount of individual-level heterogeneity incorporated in the movement data greatly influences our ability to predict the source location. The most accurate predictions were obtained using reported travel histories to describe movements of infected individuals, but using detailed simulation models to estimate movement patterns offers an effective fast alternative. Secondly, once the source is identified, we show that our model can be used to accurately determine the population likely to have been exposed to the pathogen, and hence predict the residential locations of infected individuals. The results give rise to an effective control strategy that can be implemented rapidly in response to an outbreak.

COVID-19 cluster surveillance using exposure data collected from routine contact tracing: The genomic validation of a novel informatics-based approach to outbreak detection in England.

Contact tracing was used globally to prevent onwards transmission of COVID-19. Tracing contacts alone is unlikely to be sufficient in controlling community transmission, due to the pre-symptomatic, overdispersed and airborne nature of COVID-19 transmission. We describe and demonstrate the validity of a national enhanced contact tracing programme for COVID-19 cluster surveillance in England. Data on cases occurring between October 2020 and September 2021 were extracted from the national contact tracing system. Exposure clusters were identified algorithmically by matching ≥2 cases attending the same event, identified by matching postcode and event category within a 7-day rolling window. Genetic validity was defined as exposure clusters with ≥2 cases from different households with identical viral sequences. Exposure clusters were fuzzy matched to the national incident management system (HPZone) by postcode and setting description. Multivariable logistic regression modelling was used to determine cluster characteristics associated with genetic validity. Over a quarter of a million (269,470) exposure clusters were identified. Of the eligible clusters, 25% (3,306/13,008) were genetically valid. 81% (2684/3306) of these were not recorded on HPZone and were identified on average of one day earlier than incidents recorded on HPZone. Multivariable analysis demonstrated that exposure clusters occurring in workplaces (aOR = 5·10, 95% CI 4·23-6·17) and education (aOR = 3·72, 95% CI 3·08-4·49) settings were those most strongly associated with genetic validity. Cluster surveillance using enhanced contact tracing in England was a timely, comprehensive and systematic approach to the detection of transmission events occurring in community settings. Cluster surveillance can provide intelligence to stakeholders to support the assessment and management of clusters of COVID-19 at a local, regional, and national level. Future systems should include predictive modelling and network analysis to support risk assessment of exposure clusters to improve the effectiveness of enhanced contract tracing for outbreak detection.

AmWeb: a novel interactive web tool for antimicrobial resistance surveillance, applicable to both community and hospital patients.

BACKGROUND: Antimicrobial resistance (AMR) is recognized as one of the most significant threats to human health. Local and regional AMR surveillance enables the monitoring of temporal changes in susceptibility to antibiotics and can provide prescribing guidance to healthcare providers to improve patient management and help slow the spread of antibiotic resistance in the community. There is currently a paucity of routine community-level AMR surveillance information. METHODS: The HPA in England sponsored the development of an AMR surveillance system (AmSurv) to collate local laboratory reports. In the West Midlands region of England, routine reporting of AMR data has been established via the AmSurv system from all diagnostic microbiology laboratories. The HPA Regional Epidemiology Unit developed a web-enabled database application (AmWeb) to provide microbiologists, pharmacists and other stakeholders with timely access to AMR data using user-configurable reporting tools. RESULTS: AmWeb was launched in the West Midlands in January 2012 and is used by microbiologists and pharmacists to monitor resistance profiles, perform local benchmarking and compile data for infection control reports. AmWeb is now being rolled out to all English regions. CONCLUSIONS: It is expected that AmWeb will become a valuable tool for monitoring the threat from newly emerging or currently circulating resistant organisms and helping antibiotic prescribers to select the best treatment options for their patients.